This invention relates to a heat absorber and more particularly relates to a replaceable and rechargeable or regenerable heat absorber. Further, this invention relates to the combination of electrical apparatus which produces heat when operating and to a heat absorber for absorbing such heat, particularly a replaceable and rechargeable or regenerable heat absorber. Still further, this invention, by way of example and not by way of limitation, relates to the combination of thermal or infrared (IR) imaging apparatus including electrical apparatus such as, and by further way of example and not by way of limitation, printed circuit boards which produce heat when operating and to a heat absorber for absorbing such heat, particularly a replaceable and rechargeable or regenerable heat absorber.
Thermal or infrared (IR) imaging apparatus are known to the art for providing an image in the visible spectrum, viewable by the human eye, of an object emitting or radiating infrared heat or energy. Such apparatus include thermal or infrared (IR) imaging apparatus for use by a fireman in a smoke filled burning building which apparatus enables the fireman to see, for example, the image of a human being suffering from smoke inhalation and lying unconscious on the floor but which human being is still alive and therefore radiating infrared heat or energy. Thermal imaging apparatus, of course, are inherently heat-sensitive, particularly the infrared detector and the thermoelectric cooler if included, and typically require a substantially constant operating temperature to produce suitable images. It is known to provide thermal imaging apparatus used by a firefighter with insulation to reduce the amount of heat transferred to the interior of the body of the apparatus by convection and radiation from the heated environment and particularly to the internally mounted infrared detector. An example of prior art thermal or infrared (IR) imaging apparatus is disclosed in U.S. Pat. No. 5,089,914 patented on Feb. 18, 1992, John A. Prescott, inventor, and entitled THERMAL CAMERA ARRANGEMENT; this patent is incorporated herein by reference as if fully reproduced herein.
Many different types of heat absorbers are known to the art including heat absorbers which are provided in combination with electrical apparatus which produces heat when operating and wherein the heat absorbers absorb the heat to prevent the heat from impairing the performance of the electrical apparatus and even damaging such apparatus. Heat absorbers are known to the art which include phase change material which changes phase, for example, from a solid state to a liquid state, to absorb heat produced by, for example, electrical apparatus. Such phase change material heat absorbers may include microencapsulated phase change material which may be of the type, for example, disclosed in U.S. Pat. No. 4,361,182 patented on Nov. 30, 1982, Stanislaw Michalak, inventor, and which patent is hereby incorporated herein by reference as if fully reproduced herein. A heat sink or heat absorber incorporating such microencapsulated phase change material is disclosed in U.S. Pat. No. 5,007,478 patented on Apr. 16, 1991, Subrata Sengupta, inventor, and which patent is hereby incorporated herein by reference as if fully reproduced herein. Further, a method of using microencapsulated thermal conducting absorbing materials, or phase change materials, to cool heat sources such as an electrical component is disclosed in U.S. Pat. No. 5,224,356 patented Jul. 6, 1993, David P. Colvin, et al. inventors; this patent also discloses how to fabricate microencapsulated phase change materials and this patent is hereby incorporated herein as if fully reproduced herein.
As known to the art, certain microencapsulated phase change materials appear as fine, free-flowing powders but actually consist of millions of durable capsules which contain heat absorbing core materials. These microencapsulated phase change materials can range from to several hundred microns in diameter. The core can comprise 80-85% of the material's weight, and the impermeable wall surrounding the core is typically less than one micron. These microencapsulated phase change materials are available in either a dry powder or within a liquid slurry. Such microencapsulated phase change materials are known to absorb or release large amounts of heat without a corresponding change in temperature. Microencapsulated phase change materials are available from Frisby Technologies, Inc. of Winston-Salem, N.C., under the trademark THERMASORB, and from PCM Thermal Solutions of Naperville, Ill.